Ore-treating process



' 25 precipitat' .PatcntedDec. 16, 1924s PATENT OFFICE.

rm I. renew, or .mcxson, cann onms.

' on'n-rnna'rmernocnss.

To all whom it may concern:

Be it'known that I, FRANK M. DARRQW, a. citizen of the United States, residing at Jackson, county of Amador, State of Cali l fornia, haveinvented certain new and useful Improvements in Ore-Treating Processes; and I do declare the following to be a full, clear, and'exact description of the same. n This invention relates to improvements in ore-treating processes ofa hydro-metallur cal nature, and Particularly to a process or the treatmento precious metals from being isolated and removed from the ores by the ordinary cyaniding treatments or processes.

The steps usually taken in carrying out these ordinary processes are well known and need not be set forth here. Most ores yield 90 readily to such treatments, but occasionally an ore is found which contains one or more elements which have a tendency to either prevent the economical dissolution of the precious metals, or havea decomposmg or I action prematurely removing the dissolv .metals fromthe cyanide solution; This behaviour is manifested mainly by those'orswhich contain graphitic-schists or other metamorphosed carbonaceous mats0 ter, which when brou ht in contact with the ordinary cyanide so uticnt has the detrimental effect of prematurely precipitating out the gold and [silver "from the solution. Since the once precipitated metals cannbt be ee redissolved-by any strength of cyanide solution, the latter when withdrawn contains such a small percentage of the precious metals as to render cyaniding unprofitable.

. I am awarethat recovery of the precious 40 contents of such ores has been attem ted as for instance bydrying and t ores,

after which cyamding can bereadily carriedout, but the e of laborvand'fuel incident to such treatment renders this I method uneconomica'l and from a commercialstandpoint. M

Other methods have also been tried out, I but they all, as far as I am aware, are defective, in that theyincurtoo'muchexpense or fail to recover a sufiicient percentage of the precious metals which his desired to save. r w

The principal object wf my invention then be likewise successfully certain g'old and silver o'res' which contain elements which prevent the -elementa. I l K 'As previously stated, the carbonaceous Application Med Aug: 1, i922. Serial n. 570,087.

therefore is to provide an ore treatment process for ores of the above named character by means of which the ores may first be successfully and economically treated in the wet state and left in such a condition that the ordinary cyaniding process may and economically applied thereto.

A further object is to provide such a process as may be-successfully' used in the treat-; ment of oil flotation concentrates, containing graphitic or carbonaceous matter.

In the past, large quantities of refractory ca'rbonaceousgold ores have been rejected into tailing iles, but these old '"piles may now be han ed over again andtreated by my process, and an economic extraction ob tamed. I

general my process consists in first pulverizf the ores, and then treating them with alkaline salts of certain organic acids,

after which the ores may be cyanided in the ordinaryway and a. good extraction of the precious metals obtained.

-' The best results are obtained by treatili the pulverized ore or ore-pulp with a wea solution of certain of the sodium or potassium salts of organic acids, such as the l higher members of the series G I-1 0 as myristic, 'lauric, stearic or also'thesalts of oleic acid an certain others that form, alkali salts.

- Since these-organic com ounds form the cial laundry soaps, in practice, .common soap, or by-pr'oducts, from soap works, 'or other saponaceous substances, can be' used 'asthe source of the necessary or anic salts.

If desired however the saponaceous -substance'may be prepared especially for-my. purpose so as to contain the most 'deslrable matter in the-ores'toibe thus" treated inter force with, the efiectual'solutioh of the gold almitic acids;

-main constituent .of or nary .commer- 7 andsilver, a'ndIhave found by experiment that this interference can be overcome by the use of certain organic comqpgmds, particularly those of the. nature a vestated. I take advantage of this however in .my

process, by feeding theorganic chemical to the pulp, after which the carbonaceous matter ceases to. interfere, and will permit the gold and silver in the ore to be dissolved from-such detail may be resorted to as do t and extracted when the usual process is applied. invent on as defined by the appended clanns." In practice, itmay be found beneficial to Havlng thus described my mvention, .5 add an acid to some ores, in combination What I claim asnew and useful and desire with the saponaceous matter, or before or to secure by Letters Patent, is z' after the latter. In other instances,.it may j 1. The process of treating gold and silbe desirable tokeep the pulp either neutral ver bearing tailings containing a substance or basic. Again, with some ores this organic"; tending to join to and hold therprecious chemicalmay be .added and. carried along metals within the pulp, consisting of neuwith the cyanide in solution. tralizing such tendency of said substance When it isdesired tolsettle or filter theby feeding into the pulp a solution of the pulp, some agent such as'lime or other coagsodium or potassium salts of the organic ulating agent should be used. acids of the higher members of the series After the gold has been dissolved should o,,H,,.o and extracting the precious metals the soap in solution be found to interfere by cyanide solution. a with the recovery of the precious metals j2.--The process of treating gold and silver from thecyanide solution, it may be reores containing a substance tending to hold moved b adding calcium chloride or alumithe precious metals within the ore, consist- .num sulphate to render the soap insoluble, ing of feeding directly into theore an aque- ,or some other substance, to decompose the ous solution of a soluble soap, and employsoa c 1 1 desired, the soapy compound in solu-' 3.'The process of treating gold and silver tion may be removedgjand' recovered for fubearing ores contain some materials inture use with other batches of ore by was :terferin with the removal ojthe precious ing, filtration, settling, or any othermeans, metals om the ore by ordinary. cyanidar suitable for the purpose. Q'tion, consisting of overcomin such intereyaniding not form a departure from the spirit of the mg cyanide to extract the preciousmetala- It willbe noted that apart from grinding ference by means of a saponi ed substance the ore, which is necessary in any event for of a soluble nature, and cyaniding the ore the cyanidin of the ore, no violent action' for its precious metals.-

or mechanica .expenditure of power is nec-T' 4. The process of treating gold and silver essary in carrying out my process, since the bearing. ores containin a re-precipitating reagents that I use are ver soluble in water, element, consisting of, st treating the lore and when dissolved and ed in liquid form? in a pulverized condition with a soap soluto the pulp under treatment may merely 1 tion to an amount in excess of thatbnecesdifiuse themselves through the pulp and. sary to neutralize the re-precipitating elethus mingle with the elements therein to acment, then recovering. or removing the excomplish their purpose.

Unlike an oleaginous substance these solujecting the to ble reagents do not interfere with mercury treatment.

amalgamation, should it bedesirable to use. 5. The process this method of gold recovery along with ores containing carbonaceous'matter, con-.- the cyaniding process. v v sisting of treating the ore in a pulverized This kind of ore is sometmes treated b condition with a soapsolution in quantity the oil-flotation method to remove the de sufiicient to neutralize the re-precipitating eterious graphitic matter. in a ,frothy contendency of said matter, and then centrate, after which theoil-flotation (lie-gto the orewhil'e still 'in' contact with the due is sub ected to the" usual cyani g-= soap solution some agent toprecipitate the treatment. J soap, whereby to leave the treated ore in As practised however, this process is un--. condition to be su satisfactory inasmuch as a large percentage treatment.

of the precious metal content goes into-the 6.,The process of treatin carbonaceous frothy concentrates along with the deletegold ore which consists of a ding thereto a rious matter, since the metals are mingled soluble saponaceous com' ound to protect directly with such matter. Such a concen-l lthe gold from the action o the carbonaceous he gold to be distrate could not ordinarily be then treated by,- the cyanide method, but'my process may be,"

i applied to these'concentrates with excellent 13f results as regards the percentage of pre-' cious metals recovered when t econcen' j; trates, after being treated by my process,--'

are subject to a cyanide solution.

-While this specification sets forth in dejectincg the crew the action of c anide. tail the pgesent and preferred ste s of the 8. he process 'of'treating gol and silver 35 process, stfil in practice such eviationsfores containing some substance caus ng matter, and permitting solved and extracted by cyanide.

7. The processor treating gold and silver bearing ores containing carbonaceous fmatter, consisting of treatm'g the ore in aipulverized condition with a soap solution in combination with an acid, and then sub- 1 cess of said soap solution, and finally subore thus treated to a cyanide of treating gold and silver i bjected to a cyanide u premature precipitation of the precious metals from a cyanide solution, consisting in previously adding thereto a semi-colloidal solution of a fatty acid 'salt to protect the gold and silver from being prematurely precipitated by said substance, and then removing the precious metals in solution with an alkaline cyanide, and finally treating this efiuent solution for the recovery of the pre- 10 cious metals.

9. The process of treating gold and silver flotation, and then treating the flotation concentrates with a soluble saponaceous reagent, after which cyanide is applied to &issolve the precious metals.

In testimony whereof I afix my signa ture.

FRANK M DOW. 

